Ontario Mineral Inventory

Ontario Geological Survey
Permanent Link to this Record: MDI000000002137

Record: MDI000000002137

General

Commodities

Primary Commodities: Palladium, Platinum

Secondary Commodities: Gold, Copper, Nickel

Location

Township or Area: Lac Des Iles Area

Latitude: 49° 10' 2.88"    Longitude: -89° 36' 35.47"

UTM Zone: 16    Easting: 309759   Northing: 5449352    UTM Datum: NAD83

Resident Geologist District: Thunder Bay South

NTS Grid: 52H04NE

Point Location Description: Trench

Location Method: Data Compilation

Access Description: The Lac des Iles Mine property is located approximately 90 km northwest of the city of Thunder Bay. Access to site is provided by travelling 94 km north along Highway 527 to the Lac des Iles Mine Road and then travelling west for 16 km to the mine site. The Sheriff Zone is located immediately south of the Roby Pit. It occupies the space previously designated as the Twilight, Powerline, South Pit and Southeast Roby zones.

Exploration History

1998: Lac des Iles Mines Ltd. conducted prospecting, stripping/trenching, channel sampling, geological mapping, and geophysical surveys. 1995: Lac des Iles Mines drilled 6 DDH totalling 769.6 m. 1999: North American Palladium drilled 2 DDH totalling 407.8 m. 2000: North American Palladium drilled 32 DDH totalling 18,435.5 m. 2014-15: North American Palladium Ltd. conducted resource definition drilling.

Assessment Work on File

Geology

Province: Superior

Subprovince: Wabigoon

Terrane: Marmion

Geological Age: Archean   Geochronological Age: 2699 Ma   Geochron. Age Ref.: Stone and Davis, 2006

Lithology

Lithology Comments

Dec 15, 2017 (Therese Pettigrew) - The Mine Block Intrusion (MBI) is a small, teardrop-shaped mafic complex with maximum dimensions of 3 km by 1.5 km with an elongation in an east-northeast direction. The MBI consists of gabbroic (noritic) rocks and metamorphosed and/or hydrothermally altered equivalents with highly variable plagioclase-pyroxene proportions, textures and structures. Accessory igneous minerals include magnetite and titanium-rich magnetite, ilmenite, and quartz-feldspar granophyre. The MBI was emplaced into predominantly intermediate composition orthogneiss basement rocks. The emplacement age of the MBI has been established by precise uranium-lead zircon methods as 2,689 to 2,693 Ma (Stone and Davis 2006 and references contained therein). The MBI geology is dominated by gabbroic, melanogabbroic and leucogabbroic rock types.

Mineralization

Mineralization Comments

Dec 15, 2017 (Mark Puumala) - The following is excerpted (with some minor modifications) from the Lac Des Iles Mine NI 43-101 Technical Report that is dated June 6, 2017. The Sheriff Zone is a combination of the former Southeast Roby, Twilight and South Pit zones connected through additional drilling and with some material recently moved into a NI 43-101 compliant resource (McKinnon et al., 2014; Peck et al., 2015). The Sheriff Zone is generally poorly exposed. It appears to comprise abundant varitextured gabbro and local pyroxenite and heterolithic gabbro breccia with the best palladium grades appearing to follow east-northeast striking shear zones (parallel to the Offset fault) and north-trending faults and high-strain zones. The Sheriff Zone has been subdivided into North and South zones based on their location relative to the Offset fault. Definition drilling in the Sheriff North zone in 2014 and 2015 delineated a south plunging pit-grade resource that appears to track along an apparent north-striking structure. The higher-grade core of this mineralization is referred to as the Powerline subzone that occurs immediately south of the southern edge of the Twilight Zone pit. A new surface mining operation has been proposed to extract the higher-grade portion of the Sheriff North zone that has returned several drill intersections of >4 g/t Pd over core lengths of >20m including one intersection of 18 g/t Pd over a core length of 12 m (see NAP press releases dated October 16, 2014 and February 10, 2015). The Powerline subzone occurs in an area with abundant, narrow mafic and intermediate dikes. The highest-grade palladium mineralization encountered to date in the Sheriff North zone generally occurs in varitextured gabbro or pyroxenite containing trace to minor disseminated sulfide. The Sheriff South zone is a south-plunging zone of Pd enrichment in which the principal host rock is varitextured gabbro. The zone has been traced from a few metres below surface to a depth of ~300 m.

Mineral Record Details

References

Publication - Feasibility Study Incorporating the Life of Mine Plan for Lac des Iles Mine

Publication Number: 2017 NI 43-101 Date: 2017

Author: Buss, B., Roney, C., Peck, D., Decharte, D., Marrs, G., Canosa, J., et al.

Publisher Name: Nordmin for North American Palladium

Location: SEDAR

Publication - A Preliminary Economic Assessment of the Mine Expansion Plan

Publication Number: 2015 NI 43-101 Date: 2015

Author: Peck, D., Decharte, D., Penna, D., Roney, C., Young, B., Duinker, R.

Publisher Name: Hatch for North American Palladium

Location: SEDAR

Map - Precambrian Geology, Lac des Iles Area

Publication Number: P3532 Scale: 1:50,000    Date: 2003

Author: Stone D., Fell M., Daley A., Schnieders B.R., Scott J.F., Nielsen P., Wagner D.

Publisher Name: Ontario Geological Survey

Location:

Publication - Field Trip 3 – Lac des Iles Mine; In: 58th Annual Meeting, Institute on Lake Superior Geology 2012, v. 58, pt. 2, p. 56-66

Publication Number: ILSG v. 58 Date: 2012

Author: Smyk, M., and Corkery, J.

Publisher Name: ILSG

Location:

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For detailed information regarding this mineral record please contact the Thunder Bay South Resident Geologist District Office